Migrate remaining encrypted-column lookups to the blind index

Completes the set of queries that matched a freshly encrypted value against a
stored one, which only works while encryption is deterministic. Each keeps its
original comparison and adds an index comparison in the same WHERE, so nothing
changes today.

- passenger sign-in by email, service-staff sign-in, Firebase token lookup
- driver lookup by phone and by national number
- admin ride lookup and ride monitor (both tables)
- nabeh: driver status, user resolution, ride history, complaint submission

transit_org_admins lives in the transit database and has no index column, so
login there falls back to decrypting the small set of active admins and
comparing normalised numbers.

Schema: adds users.email_bidx/phone_bidx and driver.national_bidx with their
indexes.

Verified that every :*_bidx placeholder introduced is actually bound — an
unbound one is a fatal error at request time, not a silent miss.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

backend/ride/firebase/getTokenParent.php

@@ -5,11 +5,14 @@ $phone = filterRequest("phone");
 
 // 🔐 تشفير رقم الهاتف قبل البحث (لأنه مشفّر في قاعدة البيانات)
 $phoneEncrypted = $encryptionHelper->encryptData($phone);
+global $blindIndex;
+$phoneBidx = $blindIndex ? $blindIndex->index('passengers.phone', $phone) : null;
 
 // 1️⃣ جلب passengerID بناءً على رقم الهاتف
-$sql = "SELECT `id` FROM `passengers` WHERE `phone` = :phone";
+$sql = "SELECT `id` FROM `passengers` WHERE `phone` = :phone OR (:phone_bidx IS NOT NULL AND `phone_bidx` = :phone_bidx)";
 $stmt = $con->prepare($sql);
 $stmt->bindParam(':phone', $phoneEncrypted);
+$stmt->bindParam(':phone_bidx', $phoneBidx);
 $stmt->execute();
 $data = $stmt->fetch(PDO::FETCH_ASSOC);